<template>
  <view>
    <view class="search-box">
      <uni-search-bar :radius="100" @confirm="search" @input="input" cancelButton="none"></uni-search-bar>
    </view>
    <!-- 搜索推荐列表 -->
    <view class="sugg-list" v-if="searchResults.length !== 0">
      <view class="sugg-item" v-for="(item,i) in searchResults" :key="i" @click="gotoDetail(item)">
        <view class="goods-name">{{item.goods_name}}</view>
        <uni-icons type="forward" size="16"></uni-icons>
      </view>
    </view>
    <!-- 搜索历史 -->
    <view class="history-box" v-else>
      <!-- 标题区域 -->
      <view class="history-title">
        <text>搜索历史</text>
        <uni-icons type="trash" size="17" @click="clean"></uni-icons>
      </view>
      <!-- 列表区域 -->
      <view class="history-list">
        <uni-tag :text="item" v-for="(item,i) in histories" :key="i" @click="gotoGoodsList(item)"></uni-tag>
      </view>

    </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        //延时器的timerId
        timer: null,
        //搜索框中的内容
        kw: '',
        //搜索结果
        searchResults: [],
        //搜索历史
        historyList: []
      }
    },
    methods: {
      //input输入事件的处理函数   实现防抖操作
      input(e) {
        // console.log(value)
        //清楚timer对应的延时器
        clearTimeout(this.timer)
        //重新启动一个延时器，并把timerId赋值给this.timer
        this.timer = setTimeout(() => {
          //如果500毫秒内，没有触发新的输入事件，则为搜索关键词赋值
          // console.log(e)
          this.kw = e
          this.getSearchList()
          this.saveSearchHistory()
        }, 500)
      },
      //搜索关键词
      async getSearchList() {
        if (this.kw === '') {
          this.searchResults = []
          return
        }
        const {
          data: res
        } = await uni.$http.get('/api/public/v1/goods/search', {
          query: this.kw
        })
        console.log(res, '我是搜索出来的东西')
        if (res.meta.status !== 200) return uni.$showMsg()
        this.searchResults = res.message.goods
      },
      gotoDetail(item) {
        uni.navigateTo({
          url: '/subpkg/goods_detail/goods_detail?goods_id=' + item.goods_id
        })
      },
      saveSearchHistory() {
        // this.historyList.push(this.kw)
        //这里通过set去重
        // const set = new Set(this.historyList)
        // this.historyList = Array.from(set)
        //这样可以实现，原先有的搜索记录，重新搜索时，会将其放到搜索记录的最前方
        const set = new Set(this.historyList)
        set.delete(this.kw)
        set.add(this.kw)
        this.historyList = Array.from(set)
        //将其转换成字符串
        uni.setStorageSync('kw', JSON.stringify(this.historyList))
      },
      //点击清空搜索历史
      clean(){
        this.historyList = []
        uni.setStorageSync('kw','[]')
      },
      gotoGoodsList(kw){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?query='+kw
        })
      }
    },
    onLoad() {
      //然后将字符串转换成数组，若果是一个空的话，就返回一个空数组字符串
      this.historyList = JSON.parse(uni.getStorageSync('kw') || '[]')
    },
    computed: {
      histories() {
        //注意，由于数组是引用类型，所以不要直接基于原来的数组调用reverse方法，以免修改原数组中元素的顺序
        //而是新建一个内存无关的数组，再进行reverse反转
        return [...this.historyList].reverse()
      }
    }
  }
</script>

<style>
  .search-box {
    position: sticky;
    top: 0;
    z-index: 999;
  }

  .sugg-list {
    padding: 0 5px;
  }

  .sugg-item {
    font-size: 12px;
    padding: 13px 0;
    border-bottom: 1px solid #efefef;
    display: flex;
    align-items: center;
    justify-content: space-between;
  }

  .goods-name {
    //文字不允许换行(单行文本)
    white-space: nowrap;
    //溢出部分隐藏
    overflow: hidden;
    //文本溢出后,使用...代替
    text-overflow: ellipsis;
    margin-right: 3px;
  }

  .history-box {
    padding: 0 5px;
  }

  .history-title {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 40px;
    font-size: 13px;
    border-bottom: 1px solid #efefef;
  }

  .history-list {
    display: flex;
    flex-wrap: wrap;
  }

  .uni-tag {
    margin-top: 5px;
    margin-right: 5px;
  }
</style>
